here's abc7 health and science reporter carolyn johnson. >> good left-handed pitchers are hard to come by. but ten-year-old ei don't know can also bat, catch and even play soccer well. >> i love sports. >> but in may playing pitcher and catcher nearly cost him his throwing arm. repetitive motion coupled with year around play mean little rest and recovery for young athletes. that increases the use of overuse injuries. his left elbow was on fire. >> it hurt pretty bad. >> he was in what's called a sidearm throw. he kind of drops the elbow to get the three through instead of bringing it nice and through kind of overhand getting the elbow up and around. >> the doctor at children's hospital, los angeles, treats both children and professional athletes. the sensor are tracking his precise movement patterns. she will then use motion analysis to make at judgments to his technique. >> our main goal is to work to identify these issues before an injury happens. >> he know knows how to protect his elbow but his results show he's in danger of a future knee injury. they will show him proper running,